61) Fluency Halves

Doubling and Halving to 20: Racing Snowboards

61.1 Fluency Halves Racing Snowboards


Develop fluency with one half for the wholes 12, 14, 16, 18, 20.

Prior knowledge of ten plus bonds and part-part-whole is required.


  • one half of
  • equals as “is”
  • double bond: a two-part bond, where both parts are the same


A little easier

Use Bond Blocks

Place the following blocks in a jumbled pile within reach of both players:

  • One 2 and one 4 block.
  • Two 6, 7, 8, 9, 10 blocks.

Allow students to build a part-part-whole diagram, as needed, for unknown double bonds. Often in the process of picking up the blocks students remember the bond. Touching the blocks gives processing time. Allowing students to build the whole provides reassurance and reduces anxiety. 

Part-Part-Whole diagrams

Click to download the Double Bonds to 20 Part-Part-Whole Diagrams

These part-part-whole diagrams  can be stuck to the top of student’s desk, as a desk visual, until students are fluent recalling these facts. Students with memory or processing difficulties can benefit from having visuals as permanent prompts.

Click this link to read Teacher Notes for more ideas about “Using Part-Part-Whole Desk Visuals” to support students.


In the next activity students build on double bonds using the addition strategy of near doubles. Go to

Activity 62

Doubling and Halving to 20: Near Double, Strategy Concept